Antenna system



May 1, 1951 A. c. SCHROEDER ANTENNA SYSTEM Filed May 31, 1946 FROM QVSMITTER TO'RECE/VER INVENTOR ALFRED c. SCHROEDER ATTORNEY Patented May 1, 1951 ANTENNA SYSTEM Alfred C. Schroeder, Feasterville, Pa., assignor to Radio Corporation of America, a corporation of Delaware Application May 31, 1946, Serial No. 673,268

Claims.

The present invention relates to ultra short wave antenna systems and more particularly to means for increasing the signal pick up of such antennas at extreme ranges.

An object of the present invention is to increase the signal arriving at the'input terminals of an ultra short wave receiver.

Another object of the present invention is to improve television and other short wave reception.

Another object of the present invention is to increase the distance over which television programs may be received.

The foregoing objects and others which may appear from the following detailed description are attained by providing a number of parallel dipoles in an end on array above the receiving antenna of a television receiver. For example, the dipoles may be supported above the receiving antennas in a vertical plane and within the field radiated by the television transmitter and so disposed as to redirect the portion of the energy picked up toward the receiving antenna.

The present invention will be more fully understood by reference to the following detailed description which is accompanied by a single figure of drawing in which reference characters l0, l2, l4 and I6 represent linear conductors of, for example, light, stiif metal wire or tubing. Each of the conductors is preferably a half wave in length at the operating frequency. The conductors H! to 16 are spaced apart a distance equal to the operating wavelength and maintained in position by light insulating cords l8 and 20. The cords may be supported from a tall pole or, if extreme height is required, they may be supported from a balloon such as that indicated by reference character 22. The resultant array is so disposed as to present a flat side parallel to the arriving signal wave front. The conductors are thus all energized in an in-phase relationship. In the same plane as conductors Ill, l2, l4 and I6 and parallel thereto at a convenient lower location is located a receiving antenna 24 which is adapted to be connected to a television receiver. Antenna 24 is electrically discontinuous at its center, an insulator 3|] being provided to maintain the parts in alignment. When the conductors l0, l2, l4 and 16 are located at a height such as they will directly intercept a signal radiated from the television antenna, each of the dipoles will tend to reradiate the intercepted signal. Since the radiators are spaced one wavelength in the vertical direction the reradiated signals from all of the conductors add in an in-phase relationship in a vertical direction toward the receiving antenna 24. Antenna 24, primarily receiving its energy from the television transmitting antenna by way of reradiation from conductors 10,12, I4 and I6, may be located in such relationship to the television transmitting antenna as to be in an extremely weak or substantially inefiective radiated field.

If the conductors l0, 12, M and 16 are located at a great enough height the redirected signals may supply a number of receiving antennas 24 disposed over a considerable area. Thus large numbers of television receivers, normally below the optical horizon of a given television transmitter, may be supplied with signals of usable strength. The service area of the transmitter may thus be enlarged.

I have shown receiving antenna 24 as including a parasitic director 26 and a parasitic reflector 28 whereby the sensitivity of the receiving antenna is concentrated in an upward direction. Normally director 26 will be shorter than antenna 24. I have therefore shown insulating members 30 at each end, to make its length 'equal to that of the others. This may be desirable since any direct pick up by the receiving antenna might possibly be in an opposing relationship to that received in the redirecting radiators l0, l2, l4 and I6, thus resulting in an actual diminution of the received signal strength or in the formation of ghost images on the picture screen.

It should be clearly understood that while I have shown one particular means of increasing the vertical directivity of the receiving antenna 24, the present invention is not limited thereto.

While I have illustrated a particular embodiment of the present invention, it should be clearly understood that it is not limited thereto since many modifications may be made in the several elements employed and in their arrangement without departing from the spirit and scope of the invention.

What is claimed is:

1. An antenna system including a plurality of parallel conductors each having a length substantially equal to one half of the operating wavelength, said conductors being insulated from each other and disposed in a plane perpendicular to the direction of desired maximum response, said conductors being spaced apart a distance equal to one wavelength at the operating frequency, and an antenna arranged in said plane and parallel to said conductors.

2. An antenna system including a plurality of elongated conductors each having a length substantially equal to a half wavelength at the operating frequency, said conductors being insulated from each other and arranged parallel to each other at intervals of substantially one wavelength at said frequency to define a plane, and an antenna comprising a center-fed dipole element, a reflector element and a director element arranged parallel to each other in said plane at one side of said conductors and having the radiation characteristic thereof arranged in the direction of said'conductors, whereby radio frequency energy arriving from a direction normal to said plane impinges on said conductors in broadside antenna fashion and .is reradiated by said conductors in end-fire antenna fashion and induced in said antenna in end-fire antenna fashion.

3. An antenna system including a plurality of parallel conductors each having a length sub stantially equal to one-half of the operating wavelength, said conductors being insulated from each other and disposed substantially in a plane perpendicular to the direction of arrival or a desired signal, said conductors being spaced apart a-distance substantially equal to one wavelength at the operating frequency, and an antenna arranged substantially in said plane and parallel to said conductors.

4. An antenna system including 'a plurality of parallel conductors each having a length substantially equal to one-half the operating wavelength, said conductors being insulated from each other and disposed substantially in a plane perpendicular to the direction of desired maximum response, said conductors being spaced apart a distancesubstantially equal to one wavelength at the operating frequency, an antenna arranged substantially in said plane and parallel to said conductors, the maximum sensitivity of said antenna lying along a line in said plane, and means for coupling said antenna to transducer apparatus.

5. An antenna system for increasing the area over which signals may be received, including a plurality of parallel conductors insulated from each other, each of said conductors having a length substantially equal to one half of the operating wavelength, said conductors being disposed in the path of propagation of desired signals and substantially in a plane perpendicular to the direction of maximum response, said conductors being spaced apart a distance substantially equal to one wavelength at the operating frequency, an antenna arranged substantially in said plane below and parallel to said conductors, and means for coupling said antenna to transducer apparatus.

ALFRED C. SCHROEDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,650,461 Nilson Nov. 22, 1927 1,708,515 Meissner Apr. 9, 1929 1,745,342 Yagi Jan. 28, 1930 2,028,857 Zworykin Jan. 28, 1936 2,031,065 Posthumus et al. Feb. 18, 1936 2,064,961 Tidd Dec. 22, 1936 2,183,784 Carter Dec. 19, ,1939 2,380,519 Green July 31, 1945 FOREIGN PATENTS Number Country Date 495,019 Great Britain Nov. 4, 1938 OTHER REFERENCES Radio Engineers Handbook, by F. E. Terman, first edition, published by McGi'aw-Hill 3001100., New York, 1943, pages 798-799. 

